Near-Infrared Light-Activated Pt@Au Nanorings-Based Probe for Fluorescence Imaging and Targeted Photothermal Therapy of Cancer Cells

Gold-based nanomaterials are widely used in the field of photothermal therapy (PTT) of cancer cells because of the low cytotoxicity and excellent photothermal conversion efficiency upon near-infrared (NIR) light irradiation. Hollow gold nanoparticles exhibited enhanced interaction with light and surrounding media due to larger exposed surface than solid nanoparticles and can be used to develop sensitive NIR sensors in biomedicine. Here we designed an NIR light-controlled biosensing strategy that employs dual Pt@Au nanoring@DNA (PAD) probes for fluorescence imaging and targeted PTT of cancer cells. The probes had Au nanoring with Pt framework (Pt@AuNR) as a photosensitizer and functionalized double-stranded DNA (dsDNA) hybrids as a sensor. The cell-subtype-specific recognition and fluorescence imaging were controlled by NIR light irradiation through the dehybridization of dsDNA as a result of temperature elevation localized on the PAD probe. The targeted PTT of cancer cells was excellent under the control of NIR light due to the strong absorption of Pt@AuNRs in the NIR region. The majority of target tumor cells were killed under the photothermal effect after incubating with the dual PAD probes and receiving artificial laser irradiation. The dual PAD probe system successfully described NIR light-activated cancer cell diagnosis and therapy, including the activation of specific recognition, fluorescence imaging, and targeted PTT. This work has provided a promising platform on which NIR light-controlled targeted theranostic may be developed.